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(No Model.) 3 Sheets-Sheet- 1. A. STARK.

ADDING MACHINE.

No. 308,528. Patented Nov 25, 1884.

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.WITNESSES: INVENTOR L/ K ZM,

ATTORNEYS (No Model.) S'Sheets-Sheet 2.

. A. STARK.

ADDING MACHINE.

No. 308,528. Patented Nov. 25, 1884.

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WITNESSES (No Model.) 3 Sheets-Sheet- 3.

A. STARK.

ADDING MACHINE. No. 308,528 Patented Nov. 25, 1884.

UNITED STATES PATENT ANDRE? STARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO L.\V. NOYES, OF SAME PLACE.

ADDlNG-MACi-HNE.

EPECIPICATION forming part of Letters Patent No. 308,528, dated November25, 183%.

Application filed October 18, 1883. (No model.)

1'0 all whom it may concern/.-

Be it known that I, ANDREW STARK, a citizen of the United States,residing at Chicago, in the county of Cool; and State of Illinois,

have invented certain new and useful I1nprovements in Adding-Machines,of which the following is a specification.

My invention relates to machines for producing a visible registration ofthe sum of any numbers by manipulation of finger-keys corresponding tothe digits of which the numbers to be added are composed. Itsdistinctive features are fully set forth in the claims, reference beinghad to the accompanying drawings,

I 5 wherein Figure 1 is a front elevation. Fig. 2 is a horizontalsection of the number-rollers and their common arbor. Fig. 8 is a planview. Fig. 4 is a side elevation. Fig. 5 shows the triple cam.

The entire mechanism is attached to and held in place by the base A andthe sides AA.

B B are rollers placed on a common axle, b, and adapted to revolveindependently of each other, and each having its periphery divided intothree or more equal spaces by the notches b, and each space subdividedinto ten subdivisions, numbered from O to 9, inclusive. Each roller hason one side, and rigidly secured to it, a notched disk or ratchet-wheel,b, having as many equispaeed teeth as there are equal numbered spaces onthe periphery of the rollers. On the other side each roller, except thelast one to the left, has secured to it 3 5 a triple cam, if, having aface, b", and a projection, 12 corresponding to each of the notches b onthe periphery of the roller.

0 is a bar passing across the top. and bent down at the sides of thesystem of rollers and fixed upon the shaft 1), and having a series oflight springs attached to it in such manner that one end of each maypress on the periphcry of one of the rollers and fall into the notchesI). The bar is held in placethat is, pre- 45.. vented from revolvingaround the shaft I) while the rollers are being operated by the notchedprojection a of the side frame A.

D D are parallel lever-arms, attached to the rock-shaft D, which ispivoted in the frame 5 A A behind the system of rollers B, and has aspring, D for throwing back the lever-arms D D alter being pressed downin the act of adding a number. as hereinafter described. These twolever-arms D D extend past the ends of the system of rollers B, and areconnected across the front of the machine by the key-bar D", to whichare pivoted eight keys, (1, numbered from 0 to S, inclusive. A ninthkey, (Z, numbered 9 is rigidly secured either to the key-bar D" or toone of the side bars D as shown. The side bars D are also connectedacross the front of the machine by the cross-bar D which serves for astop for the keys (Z, rocking over their pivots on the keybar D, ashereinafter explained. The piv- 6 oted keys (Z are formed and placed. soas to stand when at rest with their upper fac s in clined downwardtoward the machine, being thrown into that position by suitable springs,d" as soon as the pressure of the linger is removed. The pivoted keyshave each atoc, d, which projects considerably below the point at whichthey are pivoted, so that as the keys are presseddownward, overcomingthe spring (1*, the toe is thrown forward suiliciently to cause it tostrike upon its proper stop. The ninth or rigid key has a similar toe,(l, which stands always in position to collide with its proper stop whenthe key-bar is sulliciently depressed.

From tnc lever-arms there are projected upward and backward two pieces,1)" D, one at each end of the machine, and in front of the axis of therollers, having on their under edges segment-racks, which engage withthe segment-pinions E to impart motion to the driving-pawl E. Thesesegmcntpinions are pivoted upon the shaft I), one at each end of thesystem of rollers 15. From each of them an arm, 1], extends up beyondthe edge of 0 the rollers 33, having a range of motion concentric withthe rollers 13, and just in l'ront of them, equal to nine numeral-spaceson the periphery of the rollers. The crossbar E carries a pawl, ll,which engages with the 5 ratch et-disks if, rotatin g them and theattached rollers 13 in the direction of the numbers. This bar E and itsattached pawl E carried by the sector-pinions E to which they areattached by means of the arms F at each end,

Lli

are actuated by the segment-racks D D, engaging with said sector-pinionsE E. The cross-bar E is pivoted at each end in the projecting arms E E"of the pinions E E, the pinions being pivoted to the shalt, asdescribed. The cross-bar E is of such shape that the pawl Ff slides uponbut cannot revolve about it, and is kept in contact with theratchet-disk If by the use of a suitable spring, 0, applied to thecross-bar; or the crossbar may be rigidly attached to the arms E E, andin that case the crossbar may be made round, and a suitable spring bearranged to directly actuate the pawl E F F F F are devices for carryingthe tens from one roller to the next from left to right. They arebell-cranl-t levers pivoted at their angles, respectively, on the shaftf supported in the frame A A. They are operated by the peripheral camsI), attached to the rollers B, the lower arm, f, of each having abearing-surface in contact withone oi the cams I), and adapted to beacted upon by the latter, so as to be thrown down by each of itsprojections If. The upward-projecting arm j of the bell-crank lever Fhas on its in ward edge a beariiig surlace terminating in the projectionf midway from its upper end, against which the cam Z) acts to throw backthe bellcrank lever, which has a pawl, f, on its upper end engaging inthe ratchet Z), attached to the adjacent side of the next roller to theleft. in front, and attached to the base, I have placed a verticalprojection, G, arranged to stop the descent of the key-bar l) and keys(Z. The upper edge of this projection is of varying height,eorrespomling to the key which it is intended to step, stopping l on thefirst level, 2 on the second level, 3 on the third level, etc. Insteadthe toes (2 may be made of similarly varying length, and the stop G maythen be of uni form height.

The operation of my invention may be understood from the followingdescription: The cross-bar 0, released from the catch a, which is madesulliciently elastic to be sprung aside for that purpose, is rocked backtoward the shaft D a distance of [all ten numeralspaees, the pawls 0sliding on the periphery of the rollers or number-wheels respectively.The bar 0 being then rocked forward to its first position,the pawls cengage in the notches I), which are only ten ni'uneral-spaces apart, onthe periphery of the rollers, so that in the course of the rockingmovement of the bar through ten i'ull spaces every wheel will be thusengaged by its corresponding pawl. The pawls being all in line, thenotches, and so the zeros,which are at the same distance from thenotches on all the wheels, will be brought into line, and will so standwhen the forward movement ol'the rock-bar ceases and the catch againengages it. The operator now places the pawl E so that it will work onthe ratchet of the first roller to the right (the units-roller), anddepresses the key corresponding to the figure to be added in theunits-column. The

spring (1, which sustains the key (1 upon the key-bar, being much weakerthan the spring D which sustains the key-bar itself, yields first to thepressure upon the key, permits the key to rock over the key-bar andthrow its toe (1 forward into range of the stop-bar G. Pressure beingcontinued upon the key, and the rocking motion of the key itself beingarrested by the contact with the cross-bar D", the spring D yields tothe pressure of the operator, and the key-bar is depressed until the too(1, protruded forward as explained, collides with its corresponding stopon the stopbar G and arrests the descent of the keybar. The pressurebeing removed, the springs D and d react and throw the key and key-barinto their initial position. in this motion it will be seen that thesegment-rack D has been carried with the key-bar and side bars, l) D,and that thereby the seetor-pinion E has been revolved and has carriedwith it the pawl E and the number wheel engaged by the pawl through anarc corresponding to the number of the key depressed, thereby bringinginto the position occupied at starting by the zero a figure on theperiphery t thenumber-wheel corresponding to said key. The keycorresponding to the next figure in the column is now pressed down, andin like manner all subsequent figures in the unitseolumn, where" uponthe rollers will show the sum, reading the figures which appear belowthe ends of the springs. The operator now presses upon the head. of thepawl 11", to disengage it from the ratchet Zr of the units-roller, andslides it along upon the bar E until it will. work upon the ratchet ofthe next (tens) roller, and,co1nmeneing with the first figure in thatcolumn, proceeds as before, and similarly with all succeeding columnsuntil all have been added, when the machine will show the aggregate uponthe line where the zeros stood at the be ginning.

It will be understood from the foregoing description that when anyroller has been rotated nine numeral-spaces the apex f of thebearing-surface on the upper arm, f, of the bell-crank lever F has justpassed the apex b of the cam-disk I)" on the left side of the roller B,and the pawlf" has thereby been retracted over the ratchet I) pertainingto the next roller to the left, and the point of the lower arm, f, ofthe bell-crank lever F is resting just at the root of the next camprojection, b, of the first roller, so that upon the rotation of thefirst roller one space farther the Cfllll Z), acting against thebearing-surface of the lower arm,

f, of the bell-crank lever F, drives forward the upper arm and the pawlf, and thereby advances the next roller one numeralspace. The rock-shaltl), beingbehind the axis of the number-wheels, and the rack I), being infront of that axis and the sector E, having that axis as its center, theradius of the seginent'rack B" being thereby greater than that of thesec tor E, causes the angular motion of the keybar and of the rackrocking with it to be proportionately less than the angular motion whichthe rack thereby gives to the sector and to the number-wheels revolvingwith it. As illustrated, the radius of the rack is about three timesthat of the sector, and the angular motion of the rack is therefore onlyabout onethird that of the sector, and thereby the 1110- tion of thekey-bar, and so of the hand of the operator in depressing it, is reducedapproximately to a straight line, which renders the action easier andmore rapid than if the operator were obliged at every stroke to followthe curve of the number-wheel through nearly one-third of itscircumference, or such portion of its circumference as the number to beadded should be of thirty, the whole number of spaces on the wheel.

Having thus described my invention, I claim and desire to secure byLetters Patent 1. In an adding-machine, in combination with thenumber-rollers mounted side by side on a single arbor, a gear-sector onthe same arbor, a segment rack meshing therewith whose center of motionand curvature is on the side of said arbor opposite said rack, adriving-pawl mounted on a rigid radial extension of said gear-sector,and the key-bar rigid with said segment-rack, all cooperating to makethe angular motion of the key-bar less than the resultant angular motionof the number-wheels, substantially as set forth.

2. 111 an adding-machine, in combination with the number-wheels, theiractuating leverarm and the mechanism whereby the arm actuates thewheels, a spring to retract the arm, the finger-keys mounted on the armor some fixed adjunct thereof, and having a limited range of motion withrelation to the arm, a spring to sustain each such keys on the arm outof range of the stop-bar, said keys adapted to yield in the direction ofthe motion of the arm, but to pressure less than suflicient to actuatethe arm against its retracting-spring, substantially as and for thepurpose set forth.

3. In an adding-machine, in combination with the number-wheels and theirratchetdisks, disks secured to one side of each having two or moreequispaced radial or projecting teeth adapted to act as cams, bell-cranklevers embracing the disks in their angles, respectively, and havingtheir two arms provided with bearing-surfaces adapted to be acted uponalternately by the cam-teeth of the disks, and pawls pivoted one to eachof the bell-crank levers and adapted to engage the ratchet-wheel of thenext higher denomination above the one which actuates it, substantiallyas set forth.

4:. In an adding-machine, in combination, a supporting-frame, a shaftfixed therein, a series of independently revolving numberwheels arrangedside byside upon such shaft, and having upon their peripheries notchesat each tenth numeral-space only, a rock-bar rocking over thecircumference of the wheels, and as many independent spring-pawlsthereon as there are number-wheels, said pawls arranged separately toengage the notches on the periphery of said wheels, respectively,wherebyall the wheels are simultaneously set to zeropoint atstarting,substantially as set forth.

ANDREW STARK.

Attest:

Cults. S. BURTON, Franc W. PARKER.

